Method of making fibreboard container



Feb. 11, 1964 T. l.. zlLlox 3,120,727 METHOD OF MAKING FIBREBOARD- CONTAINER Original Filed Dec. 16, 1957 2 Sheets-Sheet 1 45 if fig-5 54-/7- M24 E@ JNVENTOR.

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METHOD 0F MAKING FIBREBOARD CONTAINER Original Filed Deo. 16, 195? 2 Sheets-Sheet 2 IN V EN TOR.

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United States Patent iiice 3,120,727 Patented Feb. 11, 1964 s Claims. (ci. 53-29) The present invention relates to fibreboard containers for shipping and storing commodities and in particular to a method for filling and closing such containers. It has a iield of especial usefulness in the packaging of paper in sheet form, especially in some of the intermediate and larger sizes for which containers of the usual form and filled lby conventional methods leave much to be desired.

The containers most commonly used for such purposes are of one of two principal types, viz. the so-called slotted type and the telescoping type. Containers of the first type usually have bingedly connected side panels with a side seam made by t'rcontainer manufacturer, yand the containers are supplied to the user in tubular form folded to lie flat. The top and bottom are closed by folding in the end flaps and then the side flaps and securing them by gluing, stapling, or other means. The telescoping type is formed of two separate parts, a tray-shaped bottom and a similarly shaped cover, the cover depth being usually equal to the over-all outside height of the container. They are customarily supplied in fiat form, to the user, who bends the sides upward along the score lines provided, then bends the iiaps on opposite sides around the vertical corners and attaches them to the other sides as by stapling or gluing. In this construction the flaps at the corner joints hold the side wall of the cover away from that of the bottom, by at least the thickness of the flap, except to the extent that the sides may be sprung together. When, as is common practice, the container is sealed by `an adhesive tape run around the lower part of the sides and lapped around onto the bottom, the existence of this open space tends, as the sealed container is handled, to rupture the tape and weaken the entire structure.

:When containers of the telescoping type are used for packing paper in sheet form, it is necessary in order to introduce a pile of sheets into the box with the rigidly fixed vertical sides without damaging the edges yof `at least some of the sheets, to have the inside dimensions of the box somewhat -larger than the actual dimensions of the sheets. The packaged sheets, therefor, fit loosely in the closed container and slide about it the container is roughly handled, with the frequent result of damage to some of the sheets, particularly their edges yand corners. A further disadvantage is encountered in the use of containers of this type, particularly when of large horizontal dimensions and relatively small depth, when one of the containers is iiited by or supported at one corner. This tends to distort the original flat form ofthe sealed containenicausing the sides of the lid to slide over the sides of the bottom and thereby rupture the sealing tape around the edges of the bottom.

It is accordingly the primary object of the present invention to provide a method of packaging products in a telescoping container which is free from the aforesaid disadvantages, which will fit snugly around the product, i.e., paper sheets or other contents of the container and which can be firmly sealed around its periphery, to create a much stronger and more rigid package than heretofore obtainable in that type of container. Another object of the invention is to provide a method of packaging products, particularly products in sheet form wherein the container is easily and readily formed around the product.

Other objects and ladvantages of the invention will become apparent from the following description.

For the accomplishment of the above and related objects, I prefer to use solid or corrugated fiberboard in the form of separate bottom and cover parts, each having the form of a rectangle from each corner of which a substantially square portion, the sizes of which determine the depth ofthe container and its cover respectively, has been removed. In each part is a centrally located rectangular area, which is to form the bottom or top respectively of the completed container, said areas being outlined by score lines which, in effect, join the corners of the cut out squares. The sides of the bottom part are bent upwards and the sides of the cover part are bent downwards along the respective score lines. A band of adhesive along the bottom of each of the side-wall portions fixedly attaches the bottom of each side-wall of the cover to the corresponding portion of the side-walls of the bottom part and results in tightly closing the container. Although not essential, I regard it as desirable to seal the four vertical edges with a tape which is adhesively attached to the side-walls for a short distance on each side of the vertical edge.- The containers of the type referred to are disclosed in my application Serial No. 703,072l filed December 16, 1957, now abandoned of which this is a division.

FIG. 1 is a cross section of a closed container manutactured accordi-ng to the method herein disclosed, but illustrated as empty of contents.

FIG. 2 is a view, from below, of the blank from which the bottom of the container is formed, showing the location of adhesive `when a contact adhesive is used.

`FIG. 3 is a similar view, likewise from below, of the cover blank, showing the location of the adhesive thereon.

FIG. 4 is a top cross sectional view of one corner of the closed container taken on the line 4 4 of FIG. 1.

FiGS. 5 to 8, inclusive, are fragmentary views showing successive stages in the closing of a container in accordance with the present invention.

Referring first primarily to FIGS. 1, 2 and 3, of the drawing, the bottom part of the container is designated generally by the numeral 20, and comprises the bottom proper 211, and the four vertical sides 22, 23, 24, and 25. Over this is fitted the cover part designated generally by the numeral l39 and comprising the top 31 and the four sides 32, 33, 34, and 35. The four vertical edges of the cover, where the sides 32, 33, 34, and 35 meet, are advantageously, though not necessarily, sealed with tapes as illustrated in FIG. 4. The cover is held in place and the container is held rigidly closed and firmly in shape by a band of adhesive 41 along the inside bottom edges of the cover side-walls 32, 33, 34, and 315, which unites the side-walls of the cover Ato -those of the bottom throughout Ithe entire periphery. This band of adhesive advantageously reaches not more than about half way up` the side-wall. A cutting line 412, which is desirably parallel to the top and bottom of the container and near the midpoint of the height, but slightly above the top of the adhesive band 41, is advantageously provided, so that when the four side-walls of the cover 30 are cut around the line 42 there is no longer any attachment between the cover 30 and the ybottom 2t), and the top 31 with the depending fupper half of the side walls 32, 33, 34, and 35 now constitutes a lid which can be removed and replaced as desired.

FIGS. 1, 3 and 5-8 show clearly how the adhesive 41 reaches only part way up the side-walls but still serves to hold the container tightly closed. FIG. 1 shows clearly how the cutting line 42 is located very slightly above the top of the adhesive so that, after the cut is made, there is nothing to prevent ready removal of the cover. FIG. 4 is a horizontal section of one corner taken on the line 4-4 of FIG. 1 (above the adhesive 41), showing how the corners are closed by overlapping of the adjoining sides, even before the sealing tape 38 is applied.

Considering next the manner of forming the container from fiat blanks, reference will first be made to FIGS. 2 and 3, in which the blanks are seen from below. From these figures it will be seen that the bottom and the cover are made from substantially identical blanks, except that the blank for the cover is sufiiciently larger than that for the bottom to permit the cover to tit over the outside of the formed bottom. These blanks are in the form of rectangles from each corner of which a substantially square portion, the size of which determines the depth of the carton, has been removed. Centrally located in each blank is a rectangular area, which areas are to form the bottom 21 and top 31 of the completed container. Said rectangular areas are outlined by score lines designated in each case by the letters a, b, c, and d, which, in effect, join the corners of the cut-out squares. It is along these score lines that the side-wall portions of the bottom and the cover are folded into vertical position to form the container.

For sealing the container, a band 41 of adhesive is placed on the under side of the cover blank along the outer edges of the side-wall portions of cover 30, as shown in FIG. 3. For soluble or pressure-sensitive adhesives, this is adequate to form the required seal. These adhesives, however, have certain disadvantages. Soluble adhesives must be freshly applied, or if previously applied and dried, must be freshly rewetted when it is desired to seal the container. Seals made with such adhesives must also be held under pressure until the adhesive has set. Pressure-sensitive adhesives, on the other hand, do not need to be held under pressure, since they form a bond immediately on being pressed into contact with a suitable surface. However, because they tend to adhere, on contact, to almost any dry surface, they must be protected from contact with other objects until the parts are in position to form the desired seal. It has accordingly been found advantageous to use a known type of what will herein be called a contact adhesive. Adhesives of this type, when applied to a surface and dried, will not adhere to other surfaces, but if brought into contact with a like adhesive on another surface, will adhere on contact and firmly bind the two surfaces together. The term contact adhesive as used in the present specification and claims, is to be understood to mean a type of adhesive which, when spread on the fiberboard used, will adhere to itself but not to other materials with which it comes in contact. By use of this type of adhesive to the desired portions of the flat blanks. When dry they can be stacked ready for use and handled without adhering to one another or to other objects with which they may come in contact. In order that the cover may be cemented in place with an adhesive of this type, both of the mating surfaces must be coated therewith, For this purpose a band 43 of adhesive is applied to the under side of the bottom blank along the inner edge of the side-wall-forming portions, as illustrated in FIG. 2.

In accordance with the method of filling and closing, the cover 30 is laid at, in an upside down position as illustrated in FIG. 3. The smoothly stacked pile 50 of paper sheets, which should be of the same size as the space outlined by the score Ilines a, b, c, d, in the bottom 20, is laid in the rectangular area outlined by the score tlines in the cover 30. The four side-wall-forming portions 32, 33, 34 and 35 are then bent upward along the respective score lines contacting and, if necessary, centering and/or squaring the load, after which they spring back to a slanting position such as illustrated in FIG. 5. Then the bottom part 20 of the container has its sidewall-forming portions folded up along the respective score lines .and is then placed upside `down over the pile of paper sheets as shown in FIG. 6. If the side-Wallforming parts 32, 33, 34, and 35 of the inverted cover are held at an angle of some 50 to 60 deg. or more with the horizontal and the corresponding parts 22, 23, 24, and 25 held so they do not spread far enough to contact the adhesive 41 on the side-wall-forming parts of the cover, the part 20 can be pushed downward by applying pressure as indicated by the arrows in FIG. 6. Continued downward pressure on part 20 then causes the sidewall-forming parts 22, 23, 24, and 25 to slide on the sloping parts 32, 33, 34, and 35 until they have been forced thereby into the vertical position shown in FIG. 7. The container is then closed by exerting inward pressure, as indicated by the arrows in FIG. 7, on the side-wall portions 32, 33, 34, and 35 of the cover while continuing to exert downward pressure on bottom portion 21, as indicated by the vertical arrows in the same figure. rI`his forms the container into the shape illustrated in FIG. 8 and brings the adhesive band 41 on the cover into adherent contact with `adhesive band 43 on the side-wall portion of the bottom, thus firmly sealing the container without .the necessity of continuing the pressure until other types of adhesive have time to set. Then, if it is desired to more tightly seal the vertical edges, these can be taped as illustrated by tape 33, shown in FIG. 4.

It will be noted that at the conclusion of these operations, the filled and sealed container is upside down. This, however, is sometimes lfound to be of advantage in the lfurther handling of the containers, as well as in their packing, closing and sealing. If for any reason, however, it should be desired to pack the container right side up, this can be done by placing the load on the bottom part 2? of the container, and carrying out the operations essentially as described, except with the other side upwards.

Like other telescoping containers, the containers of the present invention accommodate themselves to slight varia tions in the height of the load, such as occur in piles of a predetermined number of sheets or a predetermined weight of paper, dueto minute variations in the thickness or bulk of the sheets. Any such slight variations in the height of the load simply make corresponding differences 'in the degree to which the cover can be pushed down to the completely closed position, and result in like differ` ences in the registry of adhesive llnands 41 and 43, which differences in registry, with bands of the usual width, are inconsequential.

The containers of the present invention fit snugly around the pile of paper sheets (or other contents) so they cannot shift inside the container and become damaged thereby. In addition the contents and the container are so snugly and rigidly interrelated that each contributed in the resistance of the entire package to damage as has been previously mentioned. The side-wall portions of the cover are in contact throughout with those of the bottom, and are adhesively united therewith entirely around their lower edges and over a substantial part of their area. This seals the container around the bottom of the cover part without use of the conventional sealing tapes, and forms a stronger and more rigid container than can be secured by the use of overlapped and stapled corners with the concentrations of stress at the staples and the lack of close contact between the side-walls of the bottom and cover parts, as found in conventional telescoping containers. It also eliminates the usual stapling and taping operations, and thereby appreciably simplifies the setting up, filling, and closing of the container.

Although the invention has been more particularly described as applied to the packing of paper, it can also be advantageously used for other commodities, particularly those of fixed form and size, e.g. cartons or cans, a definite number of which are to be packed in each container.

I claim:

1. A method of setting up, filling, and closing cartons formed of separate fiat blanks for bottom and cover, each of which is provided with, respectively, a bottom proper and top from each of which in turn extend four side-wallforming portions adapted to be folded into side-wallforming position and each being provided with a band of contact adhesive, the cover side-wall forming portions each having an adhesive-free portion disposed between the adhesive band and the top, and the bottom side-wallforming portions each having an adhesive band disposed between an adhesive-free portion and the bottom proper, whereby the respective adhesive bands on the side-walltforming portions are each in position to contact each other along the lower edge of each side-wall when the carton is completed and closed; which method comprises: supporting the cover part upside down in a substantially horizontal position; placing thereon the contents to be enclosed in the carton; folding all of the side-wall portions upward until the contents are centered and squared on said cover part; maintaining the said side-wall-portions at an angle of more than forty-five degrees with the horizontal; folding the side-wall-forming portions on the bottom to nearly a right angle and placing the bottom part over the contents, while lowering the bottom until the edges Iof its folded side-wall-forming portions contact the adhesive-free portions of the inclined side-wall-forming portions of the inverted cover; then pressing the inverted bottom part `downward until the side-wall-forming portions are forced into position closely adjacent the contents by contact with the corresponding sidewall-forming portions of the inverted cover; and then compressing all of the side-wall-forming portions `or" the cover inward while holding the bottom portion in its extreme downward position under compression until the adhesive coated portions of the inner and outer side-walls come together and adhere :firmly and thereafter removing all compressive forces from the completed carton.

2. Method deined in claim 1, wherein the four vertical edges are sealed with tape after the carton has been fully closed.

3. A method of setting up, filling, and closing cartons formed of separate at blanks for bottom yand cover, each of which is provided with, respectively, a bottom proper and top from each of which in turn extend four side-wallforrning portions adapted to be folded into side-wallforming position and each provided with a band of contact adhesive, the cover side-wall forming portions each having an adhesive-free portion disposed between the adhesive band and the top, and the bottom side-wallforming portions each having an adhesive band disposed between an adhesive-free portion and the bottom proper, whereby the respective adhesive bands on the side-wallforming portions are each in position to contact the other along the lower edge of each side-wall when the carton is completed and closed; which method comprises the sequential steps of: supporting one of said flat blanks in a substantially horizontal position; placing thereon the contents to be enclosed in the carton; folding the sidewall portions upward until the contents are centered and squared on the central portion thereof, maintaining the said side-wall-portions at an angle of more than forty-hive degrees with the horizontal; folding the side-wall-forming portions on the other of said blanks to nearly a right angle and placing the said other blank over the contents; lowering said other blank until the edges of its folded side-wall-forming portions contact the adhesive-free portions of the sidewall-forming portions of the first mentioned blank; then pressing the said second mentioned blank downward runtil the side-wall-forming portions are formed into position by contact with the corresponding portions of said rst mentioned blank into intimate contact with the contents; and then pressing opposed ones lof the interrelated side-wall forming portions of the blanks inwardly against the contents while holding the second mentioned blank in its eXtreme downward position, until the adhesive coated portions of the inner and outer side-walls come together and adhere lirmily while matintaining said yblanks stationary in a horizontal plane during said filling and forming steps.

4. The method ydened in claim 3, wherein the four vertical edges `are sealed with tape after the carton has been fully closed and the blanks adhered.

5. A method of forming a generally rectangular carton about contents to be enclosed, the carton having a bottom that telescopingly tits into a cover, the bottom and cover both being 'formed of separate iiat blanks, each of which blanks is provided with a central rectangular area -rintegral with four side-wall-forming portions adapted to be folded into side-Wall-forming position, each portion being provided with a band of contact adhesive, the cover slidewall-forming portions each having an adhesive-free portion disposed between the adhesive band and the top, and the bottom side-wall-forming portions each having an adhesive band disposed between an adhesive-free portion and the bottom proper, whereby the respective adhesive bands -on the side-'wall `forming portions are each in position to contact an opposing band of adhesive on the sidewall-forming portion `of the other blank that is adjacent thereto when the carton is completed and closed; which method comprises: supporting a rst one of said at blanks in Ia substantially horizontal position; placing thereon the contents to be enclosed in the carton; folding the side-wall portions upward until the contents are centered and squared on the central area of said rst blank; maintaining the said sideawall portions of said rst blank at an angle of more than tlorty-live degrees with the horizontal; folding the side-wall-forrning portions on the other of said blanks to nearly a right angle and placing said other blank over the contents; lowering said other blank until the edges of its folded side-wall-forming portions contact the adhesive-free portions -of the side-wallyforming portions of said first blank; then pressing said other blank downward until the side-wall-fonming portions are forced into position by contact with the corresponding portions of said first blank; and then pressing the interrelated side-wall-forming portions of the blanks inwardly while holding said other blank in its extreme downward position, until the contact adhesive coated portions of the inner and outer side-walls come together.

References Cited in the file of this patent UNITED STATES PATENTS 1,463,567 Arnold July 31, 1923 1,857,680 Van Der Pyl et al May l0, 1932 2,078,446 Grigg Apr. 27, 1937 2,215,545 Demler Sept. 24, 1940 FOREIGN PATENTS 345,351 France Nov. 29, 1904 18,136 Great Britain 1908 UNITED STATES PATENT voEEICE CERTIFICATE OF CORRECTION Patent 'No 3 I20u727 February l1 1964i Thomas L., ZILoxA It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column lv line 57v for "fted" reed lifted -m column q line 3 for "ormedH read ma forced ma,

Signed and sealed this 30th day of June I94 (SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER Attesting Officer 

1. A METHOD OF SETTING UP, FILLING, AND CLOSING CARTONS FORMED OF SEPARATE FLAT BLANKS FOR BOTTOM AND COVER, EACH OF WHICH IS PROVIDED WITH, RESPECTIVELY, A BOTTOM PROPER AND TOP FROM EACH OF WHICH IN TURN EXTEND FOUR SIDE-WALLFORMING PORTIONS ADAPTED TO BE FOLDED INTO SIDE-WALLFORMING POSITION AND EACH BEING PROVIDED WITH A BAND OF CONTACT ADHESIVE, THE COVER SIDE-WALL FORMING PORTIONS EACH HAVING AN ADHESIVE-FREE PORTION DISPOSED BETWEEN THE ADHESIVE BAND AND THE TOP, AND THE BOTTOM SIDE-WALLFORMING PORTIONS EACH HAVING AN ADHESIVE BAND DISPOSED BETWEEN AN ADHESIVE-FREE PORTION AND THE BOTTOM PROPER, WHEREBY THE RESPECTIVE ADHESIVE BANDS ON THE SIDE-WALLFORMING PORTIONS ARE EACH IN POSITION TO CONTACT EACH OTHER ALONG THE LOWER EDGE OF EACH SIDE-WALL WHEN THE CARTON IS COMPLETED AND CLOSED; WHICH METHOD COMPRISES: SUPPORTING THE COVER PART UPSIDE DOWN IN A SUBSTANTIALLY HORIZONTAL POSITION; PLACING THEREON THE CONTENTS TO BE ENCLOSED IN THE CARTON; FOLDING ALL OF THE SIDE-WALL PORTIONS UPWARD UNTIL THE CONTENTS ARE CENTERED AND SQUARED ON SAID COVER PART; MAINTAINING THE SAID SIDE-WALL-PORTIONS AT AN ANGLE OF MORE THAN FORTY-FIVE DEGREES WITH THE HORIZONTAL; FOLDING THE SIDE-WALL-FORMING PORTIONS ON THE BOTTOM TO NEARLY A RIGHT ANGLE AND PLACING THE BOTTOM PART OVER THE CONTENTS, WHILE LOWERING THE BOTTOM UNTIL THE EDGES OF ITS FOLDED SIDE-WALL-FORMING PORTIONS CONTACT THE ADHESIVE-FREE PORTIONS OF THE INCLINED SIDE-WALL-FORMING PORTIONS OF THE INVERTED COVER; THEN PRESSING THE INVERTED BOTTOM PART DOWNWARD UNTIL THE SIDE-WALL-FORMING PORTIONS ARE FORCED INTO POSITION CLOSELY ADJACENT THE CONTENTS BY CONTACT WITH THE CORRESPONDING SIDEWALL-FORMING PORTIONS OF THE INVERTED COVER; AND THEN COMPRESSING ALL OF THE SIDE-WALL-FORMING PORTIONS OF THE COVER INWARD WHILE HOLDING THE BOTTOM PORTION IN ITS EXTREME DOWNWARD POSITION UNDER COMPRESSION UNTIL THE ADHESIVE COATED PORTIONS OF THE INNER AND OUTER SIDE-WALL COME TOGETHER AND ADHERE FIRMLY AND THEREAFTER REMOVING ALL COMPRESSIVE FORCES FROM THE COMPLETED CARTON. 